Alcohol is a very powerful, addictive drug that some adults enjoy in low doses, but that is damaging or even lethal in high doses. Many adults drink moderately and safely. Yet other people drink too much and get hurt. For teens, alcohol can be very harmful -- and it's illegal.

Check out the following Q&A to update your knowledge of alcohol and teen drinking. Share this information with a friend, especially if you know someone who is an underage drinker.

What Is Alcohol?

The scientific name for alcohol that people drink is ethyl alcohol or ethanol. Beer, wine, and liquor all contain ethyl alcohol. Other types of alcohol, like rubbing alcohol (isopropyl alcohol), are poisonous if consumed.

What Happens When You Drink Alcohol?

After you drink an alcoholic beverage like beer or wine, the alcohol enters your bloodstream from your stomach and small intestine. From there, it travels to your brain. There, it slows reaction time, makes you less coordinated, impairs your vision, and -- even at relatively low doses -- leads to unclear thinking and problems making good judgments.

Is Alcohol Addictive?

Yes, alcohol is highly addictive. About 18 million adults are addicted to alcohol. This means they need to drink alcohol in order to function normally, and their drinking causes problems in their lives.

Alcohol addiction can begin at any time in someone's life. But starting to drink when you are a teenager increases the risk for addiction. About half of U.S. teens who start drinking alcohol before age 14 will be addicted to it at some point. Only 9% of people in the U.S. who wait until they turn 21 will be addicted at some point.

Is One Type of Alcoholic Drink Safer than Another?

No. All alcoholic drinks contain alcohol, and all can be just as dangerous. The more alcohol you drink, the more you will be impaired. Beer, wine, and liquor all contain different amounts of alcohol. Beer is between 3% and 5% alcohol; wine is about 12%; and liquor usually is about 40% alcohol. One beer has about the same amount of alcohol as one glass of wine or one "shot" of liquor.